Mechanical testing at scales of microns or less (e.g., from scales of microns to nanometers) is a technique used to derive mechanical properties at these scales. This is achieved by mechanically testing (e.g., scratching, indenting, tensioning or the like) a sample material with a probe and determining or measuring the forces applied (ranging from a few nano-Newtons to several Newtons) as well as measuring the depth of the corresponding indentation or other mechanical deformation to the sample material.
Probes (e.g., tips for a mechanical testing instrument that indents, scratches material or the like) used for mechanical testing at scales of microns or less come in a variety of geometries, shapes, and materials. Similarly, transducers used with the probes are configured differently to provide a variety of testing functionality (e.g., high load or low load transducers). Certain material properties are better characterized using a particular type of probe (and optionally differing transducers). Users of nano-indenters (and other testing instruments usable at these scales) use different instruments (e.g., one or more of probes or transducers) on the same material to characterize the properties of the material accurately. In some examples, to measure the properties of a material with differing probes users change the probes on the indenter transducers manually between each measurement. Manual changing of the probes significantly increases the overall measurement time (e.g., by way of removal of the previous probe and installation of a new probe, recalibration, test indentations and the like). Additionally, in other examples the manual changing of probes introduces error in mechanical testing as the exchange of probes disturbs a potentially controlled environment, for instance with the exposure of unconditioned (heated or cooled) air, manual manipulation of the instrument and transducer, or the like. Furthermore, changing the probes can be labor intensive and often frustrating, as the small probe sizes (and sensitive instruments) are difficult to hold and mechanically manipulate.
Further, probe geometry (e.g., shape and size) is important for the accuracy of measurements with mechanical testing at scales of microns or less. Probe geometry degrades with usage. In other words, each mechanical testing operation wears the probe and accordingly changes its shape and size. In some examples, software algorithms for nano-indenters (and other mechanical testing instruments at scales of microns or less) implement techniques to detect probe degradation. However, once a worn probe is detected manual changing of the probe may introduce the issues described above. Such an arrangement may be problematic for users running mechanical testing measurements at scales of microns or less over a desired extended timeframe (e.g., on an ongoing or automated basis). Probe degradation may limit the overall timeframe of such extended (repeated) measurements.
Accordingly, the changing of probes and probe degradation may limit the ability to conduct automated measurements with mechanical testing instruments at scales of microns or less.